An Approach to Increase the Fusion Tritium Breeding Ratio Using Temperature Field Balance Based on Water-Cooled Ceramic Blanket

Abstract

An advanced breeding blanket for excellent tritium breeding performance shall be designed to realize the operations of Chinese Fusion Engineering Testing Reactor (CFETR) at steady-state burning tritium fuel in the core plasma for fusion reactions. Tritium release from blanket interior effectively requires a temperature range above than 400 °C. This indicates that the blanket temperature field distribution and its evolution are related to the online tritium breeding ratio (TBR) assessment. In this article, water-cooled ceramic blanket (WCCB) models are built to perform the TBR estimation and the temperature field simulations. It is confirmed that the temperature field affects the TBR variation, which is linked to the blanket cooling pipes (CPs) layout. In addition, the effective volume fraction of tritium release of the blanket model is defined to evaluate the breeding regional proportion whose temperature is higher than 400 °C. The effective volume fraction of tritium release is analyzed for the inlet coolant temperature ranging from 0.6 to 5.0 m/s by an Eulerian-Eulerian two-phase numerical simulation method. The outer surface temperature of CPs can be raised toward 400 °C when inlet velocity is 1.1 m/s. This is a vital approach to reduce the deep temperature gradient in blanket interior, which is beneficial to the tritium release sufficiently. The estimation of critical heat flux (CHF) of first wall (FW) indicates that boiling crisis will not take place in FW. This work is helpful to the engineering design of fusion blanket considering the tritium self-sufficiency in the road toward fusion reactor.